The prevalence of sleep disordered breathing (SDB) in middle aged persons in the general population is estimated to be 4 percent in men and 2 percent in women with higher rates observed in the elderly. Accumulating evidence from retrospective and cross-sectional studies suggest that SDB is associated with the presence of cardiovascular and cerebrovascular disease (CVD) and consequent increased mortality and morbidity. However, there is little prospective data indicating whether SDB is an independent dsk factor for the development of CVD. The Sleep Heart Health Study (SHHS) is a longitudinal multi-center cohort study that was started in 1994 to determine the cardiovascular consequences of SDB. Initially, SHHS recruited 6441 participants (1996-98) to undergo in-home polysomnography (PSG) and acquisition of other CVD and sleep-related data. Another examination with repeat PSG (2001-2003) has just been completed. Mortality and morbidity follow-up is ongoing, but event rates have been insufficient to provide stable estimates of the effect of SDB on incident CVD and mortality. Additionally, a unique resource of SHHS is its archive of approximately 10,000 PSGs, associated scoring and clinical covariate data. Providing the scientific community access to this data has always been an important goal of SHHS, and has the potential to realize significant benefits in collaborative research ranging from novel methods of signal processing to identifying unique epidemiologic associations. Therefore, this application proposes additional mortality and morbidity follow-up of the SHHS cohort, continuation of longitudinal and cross-sectional data analyses focused on SDB as a risk factor for cardiovascular events and hypertension, and development of an infrastructure to facilitate access by the general scientific community to the SHHS PSG archive. These goals will be achieved by accomplishing the following specific aims: 1) to continue follow-up of the SHHS cohort in order to assess SDB as a risk factor for incident hypertension, and incident and recurrent CVD events; 2) to characterize the natural history of SDB and determine how change in RDI (# apneas or hypopneas/hour of sleep) is related to risk for interim and incident CVD events; 3) to characterize the relationship between SDB and SDB progression with quality of life and indicators of daytime sleepiness; 4) to use the PSG data as well as previous collected risk factor data from parent cohorts to develop a clinically and epidemiologically applicable model of risk relating to SDB; and 5) to develop an infrastructure to facilitate data sharing, collaborative analysis, and dissemination of data analytic tools and research findings to the scientific community. Accomplishing these goals will provide important information concerning the public health impact of SDB.